Imagine dogs screening for COVID-19 infections faster than lab tests. A pioneering study at France's National Veterinary School of Alfort is training canines to identify the virus's unique odor, with plans to deploy 100 dogs if successful.
This innovative approach comes from Professor Dominique Grandjean, a leading expert at the National Veterinary School of Alfort in Val-de-Marne and head of the veterinary service for the Paris Fire Brigade (BSPP). As quoted by Euronews on May 2, 2020, Prof. Grandjean aims to train a hundred dogs by the end of the month.
The Nosais study tests a compelling hypothesis: certain viruses and bacteria produce distinct odors, and COVID-19 may be no exception. Prof. Grandjean explains that the sweat of infected patients carries a different scent from that of healthy individuals—something dogs can detect. This stems from viral byproducts, or catabolites, excreted in sweat, stools, urine, saliva, and more. Sweat is ideal for training because it poses no risk of contamination, lacking live virus particles.
In the Nosais trial, veterinarians and firefighters present dogs with cotton swabs soaked in patient sweat. The animals learn to differentiate the COVID-19 scent among multiple samples in scent-detection traps, sitting by the correct one to earn a reward.
Participating dogs are elite performers, often specialized in explosives detection or first-aid response. If successful, they could offer a rapid, non-invasive complementary solution to PCR tests, which detect the virus in only about 70% of cases.
Similar efforts are underway in the United Kingdom, where dogs are training to sniff face masks from COVID-19 patients, aiming to confirm the disease's signature odor.
